[PATCH RESEND] cpufreq: Make sure target freq is within limits

[PATCH RESEND] cpufreq: Make sure target freq is within limits

[Viresh Kumar]

__cpufreq_driver_target() must not pass target frequency beyond the limits of
current policy.

Today most of cpufreq platform drivers are doing this check in their target
routines. Why not move it to __cpufreq_driver_target().

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
Hi Rafael,

Resend doesn't contain any change, but fixed commit log

 drivers/cpufreq/cpufreq.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 28dc134..2f5ac2d 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1470,12 +1470,19 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 			    unsigned int relation)
 {
 	int retval = -EINVAL;
+	unsigned int old_target_freq = target_freq;
 
 	if (cpufreq_disabled())
 		return -ENODEV;
 
-	pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
-		target_freq, relation);
+	/* Make sure that target_freq is within supported range */
+	if (target_freq > policy->max)
+		target_freq = policy->max;
+	if (target_freq < policy->min)
+		target_freq = policy->min;
+
+	pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
+			policy->cpu, target_freq, relation, old_target_freq);
 
 	if (target_freq == policy->cur)
 		return 0;
-- 
1.7.12.rc2.18.g61b472e

Re: [PATCH RESEND] cpufreq: Make sure target freq is within limits

[Rafael J. Wysocki]

On Friday, October 26, 2012 06:05:21 PM Viresh Kumar wrote:
> __cpufreq_driver_target() must not pass target frequency beyond the limits of
> current policy.
> 
> Today most of cpufreq platform drivers are doing this check in their target
> routines. Why not move it to __cpufreq_driver_target().
> 
> Signed-off-by: Viresh Kumar <viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> ---
> Hi Rafael,
> 
> Resend doesn't contain any change, but fixed commit log

Applied to the linux-next branch of linux-pm.git as v3.8 material.

Thanks,
Rafael


>  drivers/cpufreq/cpufreq.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 28dc134..2f5ac2d 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -1470,12 +1470,19 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
>  			    unsigned int relation)
>  {
>  	int retval = -EINVAL;
> +	unsigned int old_target_freq = target_freq;
>  
>  	if (cpufreq_disabled())
>  		return -ENODEV;
>  
> -	pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
> -		target_freq, relation);
> +	/* Make sure that target_freq is within supported range */
> +	if (target_freq > policy->max)
> +		target_freq = policy->max;
> +	if (target_freq < policy->min)
> +		target_freq = policy->min;
> +
> +	pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
> +			policy->cpu, target_freq, relation, old_target_freq);
>  
>  	if (target_freq == policy->cur)
>  		return 0;
> 
-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.